How long does it take for a refund to show up in my account

I ordered a refurbished phone from a mobile phone company and had to send it back because it was faulty.

They agreed to a refund, but have been stalling so I opened a dispute with PayPal, the company have agreed that I am due a refund and received the item back 8 days ago. In the past week I’ve had promises of a refund, firstly they were checking the item was received back, then they were processing the refund, and now yesterday they said the refund was processed and it will be showing in my account shortly.

I just wandered how long it takes from refund until it does show, I only have 3 days left to escalate the claim to PayPal.